This invention is directed generally to an improvement in valves for gas compressors, and it deals more particularly with provision of a springless discharge valve which has extremely good characteristics of positive action in terms of quick seating with no chatter while still providing a relatively high capacity gas through-put.
In my U.S. Pat. No. 3,148,697, titled "COMPRESSOR VALVE" and which issued Sept. 15, 1964, I disclosed a ball type valve which at that time represented a considerable break through in the art from the standpoint of high capacity and operation at relatively high speeds of operation for the compressor. By high speed reciprocation I refer to those compressors operating in the range of 400 to 1750 strokes per minute. The requirements for a superior discharge valve for such a compressor are positive seating at the instant of pressure reversal, and a maintenance of the ball in firm sealing contact with the seat during compression.
In the years since the development of my patented valve structure, I have devoted considerable effort to improving the structure. The improvement has resulted largely from an effort to obtain a valve which did not require any springs for seating the ball, and which would quickly and positively seat without any "chatter", that is, bouncing of the ball around on the seat thus leaving some opportunity for blow back, particularly at the higher speeds of operation.
In conducting my work along the above lines, I have discovered that there is an extremely critical relationship between the ball and seat which defines the difference between the optimum valve and one which is almost, but not quite, satisfactory. To be effective, the ball must be positively guided to the seating position, and there must be a relationship established such that the ball will not have any opportunity to bounce or rebound. By providing such an arrangement, the valve is one which permits accidental accumulation of liquid without breakage, and in addition, the wear is minimized to the point where a tight seal is maintained over a long period of time.
Such a valve makes it possible to eliminate high discharge temperatures even with high suction temperatures, and there is no danger of spring breakage (and consequent down time for replacement) since no springs whatever are required.
Other objects of the invention together with the advantages which are pertinent thereto will appear during the course of the following description.